JPS60150582A - Cooking device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a cooking appliance that includes a built-in microcomputer and that performs cooking under the control of the microcomputer.

[Technical backbone of the invention and its problems] Conventionally, a cooking device with a built-in microcomputer, such as a microwave oven, is equipped with a reset circuit that responds to the rise of the power supply voltage, and the power cord is plugged into the power outlet 1. When a power failure occurs, or when a power outage occurs and then the power outage is canceled, a reset signal is generated to reset or initialize the microcomputer, and the display on the operation panel displays 0'' or ''.
1:01" (hereinafter referred to as the Silanc display). Therefore, when using such a microwave oven, the user can know of a power outage even if he or she is not there, and can take steps such as re-cooking etc. It is convenient because it allows quick treatment.

However, some of these microwave ovens are equipped with a cancel key as a means of dealing with microcomputer malfunctions caused by noise from power lines, etc., and when this cancel key is pressed, the above-mentioned Some devices reset the microcomputer by temporarily canceling the reset signal issued from the reset circuit and then returning it again. However, in this case, each time the cancel key is pressed, a blank display similar to when the power cord is inserted or when a power outage is canceled is displayed, resulting in a problem that the reliability of the power outage notification is reduced. In other words, when the user returns to the microwave oven, if a blank display is displayed, the user may be wondering whether it is a power outage warning or if someone pressed the cancel key. It was not possible to determine whether this was caused by this. In addition, some microwave ovens display a blank display even when cooking is complete, making it even more difficult to determine whether a power outage has been reported.

FIG. 1 shows an example of a control circuit for a microwave oven equipped with a cancel key as described above. In FIG. 1, numeral 1 is a microcomputer that performs various controls related to cooking. 2 is a power supply circuit, and microcomputer 1
The operating voltage Vd (5V) is supplied to the Reference numeral 3 denotes a sensor circuit consisting of various sensors, which supplies the microcomputer 1 with information on the cooking status. A reset circuit 4 generates a reset signal R in response to the rise of the power supply voltage and supplies it to the microcomputer 1. Reference numeral 5 denotes a relay circuit that controls the heating operation section in accordance with commands from the microcomputer 1. Reference numeral 8 denotes a key matrix circuit having a large number of keys arranged in a matrix, which extracts a digit signal from the key scan circuit 7 by operating each key, and supplies it to the microcomputer 1 as a key signal. Note that this key matrix circuit 8 includes a cancel key 9. 10
A cancel key circuit controls the supply of a reset signal R from the reset circuit 4 to the microcomputer 1 in response to the operation of the cancel key 9.

FIG. 2 shows a specific example of the reset circuit 4 and the cancel key circuit 10. First, in the reset circuit 4, the operating voltage vd (5V) obtained from the power supply voltage is applied to the resistor 12 via the Zener diode 11 in the reverse direction, and to the diode between the collector and emitter of the NPN transistor 14 via the resistor 13. 15 and a resistor 16 in parallel to each other. And capacitor 1
7 is connected between the collector and emitter of an NPN transistor 18, and the transistor 18 is connected to the interconnection point of the Zener diode 11 and the resistor 12. On the other hand, in the cancel key circuit 10, the output signal of the cancel key 9 is applied to a parallel circuit of a capacitor 21 and a resistor 22, and the voltage across this parallel circuit is NPN via a resistor 23.
is applied between the pace emitter of the type transistor 24. The collector of the transistor 24 is connected to the output terminal of the reset circuit 4.

That is, as shown in FIG. 3, when the power cord is inserted into the power outlet and the power is turned on, the operating voltage Vd also rises as the power supply voltage rises. At this time, in the reset circuit 4, the operating voltage Vd is the Zener voltage value of the Zener diode 11 (for example, 3.3V).
(after a period of time), transistor 14 remains off, transistor 18 turns on, and capacitor 1
A discharge circuit for 7 is formed. When the operating voltage Vd exceeds the Zener voltage value, transistor 14 is turned on, which turns transistor 18 off.

When the transistor 18 is turned off, charging of the capacitor 17 is started with a <CR time constant based on the resistance value of the resistor 16 and the capacitance of the capacitor 17. In this manner, the voltage of the capacitor 17 is supplied to the microcomputer 1 as a reset signal R, and the microcomputer 1 is reset, or initialized, during a period in which the voltage of the reset signal R is below a predetermined level. Then, a blank display is performed on the display section 6.

Further, even when a power outage occurs and is subsequently canceled, the microcomputer 1 is initialized during the period in which the voltage of the reset signal R is below a predetermined level, and a blank display is performed on the display section 6. This blank display is to notify the user that a power outage has occurred.

By the way, when you are on standby or in the middle of cooking, press the cancel key 9.
When is pressed, transistor 2 of cancel key circuit 1
4 is turned on, the charging voltage of the capacitor 17 of the reset circuit 4 is discharged, and the reset signal R is released. When the pressing operation of the cancel key 9 is released, the capacitor 17 is charged again and the reset signal R is generated, and the microcomputer 1 is reset during the period when the voltage of the reset signal R is below a predetermined level. It will be done.

Therefore, if the microcomputer 1 malfunctions due to noise from a power line, for example, the microcomputer 1 can be initialized. However, in this case, a blank display is performed in the same way as when the power outage is canceled, resulting in the problem described above.

[Purpose of the invention]

This invention was made in view of the above circumstances,
The purpose is to provide a highly reliable cooker that can reliably notify power outages.

[Summary of the invention]

This invention has a built-in microcomputer and controls cooking by the microcomputer.
In a cooker equipped with a reset circuit that supplies a microcomputer reset signal in response to the rise of the power supply voltage, and a cancel key that controls the supply of the reset signal from this reset circuit to the microcomputer, the power supply voltage detection output of the reset circuit A delay circuit is provided that outputs a signal after a certain period of time from the generation of the reset signal in response to the reset signal, and furthermore, when the reset signal is supplied to the microcomputer, it is determined whether or not there has been a power outage based on the output of the delay circuit. A determination means is provided, and when the determination means determines that there has been a power outage, a notification means is provided to notify that fact.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. However, in the drawings, the same parts as in FIGS. 1 and 2 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

As shown in FIG. 4, a delay circuit 3o is connected to the reset circuit 4. This delay circuit 3o outputs a signal (logic "i") after a certain period of time from generation of the reset signal in response to the power supply voltage detection output of the reset circuit 4.

Here, a specific example of the main part in FIG. 4 is shown in FIG.

That is, in the delay circuit 30, the operating voltage Vd is applied to the capacitor 3 through the parallel circuit of the resistor 31 and the diode 32.
3 is applied. This capacitor 33 has NPN type 1 to
The collector and emitter of transistor 34 are connected, and the bases of transistor 1 to transistor 34 are connected to the collector of transistor 14 in reset circuit 4 via resistor 35 . In other words, the transistor 34 responds to the power supply voltage detection output of the reset circuit 4.

Therefore, the voltage across the capacitor 33 becomes a buffer C
Supplied to the R time constant circuit. The output of this CR time constant circuit is supplied to the microcomputer 1 via a resistor 40 and a buffer 41. Note that the display unit 6 is connected to an operation panel 50 on the front side of the microwave oven body, as shown in FIG.
It is set in.

Next, the operation of the above configuration will be explained with reference to FIGS. 7 and 8.

When the power supply cord 1 is plugged into an N source outlet and the power is turned on, the operating voltage Vd also rises as the power supply voltage rises. At this time, in the reset circuit 4,
Until the operating voltage Vd exceeds the Zener voltage value (for example, 3.3 VI), the transistor 14 remains off and the transistor 18 turns on, forming a discharge circuit for the capacitor 17. Also, the transistor 14 remains off. is maintained, the 1H transistor 34 in the delay circuit 30 is turned on, and a discharge circuit for the capacitor 33 is formed.When the operating voltage Vd exceeds the Zener voltage value, the transistor 14 is turned on, and the transistor 14 is turned on. 18 turns off.

When the transistor 18 is turned off, charging of the capacitor 17 is started, and the voltage of the capacitor 17 rises with a CR time constant determined by the resistance value of the resistor 16 and the capacitance of the capacitor 17, and a reset signal R is generated. Also, transistor 1
4 turns on, the transistor 34 of the delay circuit 30 turns off, charging of the capacitor 33 starts, and the voltage of the capacitor 33 increases with a CR time constant determined by the resistance value of the resistor 31 and the capacitance of the capacitor 33. In this case, resistance 3
The CR time constant of the resistor 16 and the capacitor 33 is the same as the time constant of the resistor 16 and the capacitor 17 in the reset circuit 4, so that the voltage rise of the capacitor 33 is the same as the voltage rise of the reset signal R.

When the voltage of the capacitor 33 (voltage at point A) exceeds a certain value, for example, 2.5V or more, the high voltage (
The voltage at 8 points (-5V) is output.

Then, the capacitor 39 is charged, and the voltage of the capacitor 39 (voltage at the 0 point) reaches a certain value or more, for example, 2
．． When the voltage exceeds 5V, the buffer 41 outputs a logic "i" signal (voltage at 0 point = 5V). That is, the output of the delay circuit 30 becomes a logic "1" signal after a certain time T based on the CR time constant of the resistor 37 and capacitor 39 after the reset signal R is generated (a predetermined voltage or higher).

Therefore, the microcomputer 1 receives the reset signal R.
When the voltage of the reset signal R is supplied, the reset or initialization is performed during a period in which the voltage of the reset signal R is below a predetermined level. Then, the microcomputer 1 monitors the output of the delay circuit 30 for a certain period of time T after the reset signal R is supplied (at a predetermined voltage or higher), and if the output is a logic "OII times signal", it is determined that a power outage has occurred. The determination is made and the display section 6 displays a blinking "°°O"'. However, in this case, the user knows that the blinking display is due to the power being turned on, and therefore presses the cancel key 〇. When the cancel key 9 is pressed, the transistor 24 of the cancel key circuit 10 is turned on, the charging voltage of the capacitor 17 is discharged, and the reset signal R is released. When the press of the cancel key 9 is released, the capacitor 17 is charged again and the reset signal R is generated. thus,
During the period in which the voltage of the reset signal R is below a predetermined level, the microcomputer 1 is reset, and the blinking display of '0' on the display section 6 ends.

By the way, if a power outage occurs during standby or cooking, the reset signal R is canceled as the operating voltage Vd falls. Then, when the power outage is canceled, the same operation as when the power cord is inserted is performed, and the reset signal R is generated again. Then, the microcomputer 1 is initialized during a period in which the voltage of the signal @R to the reset 1 is below a predetermined level. Further, since the output of the delay circuit 30 becomes a logic "1" signal within a certain period of time after the generation of the reset signal R- (at a predetermined voltage or higher), the microcomputer 1 determines that a power outage has occurred, and the display section 6 ``0゛'' is displayed blinking.

Therefore, the user can immediately notice that a power outage has occurred.

Further, if the microcomputer 1 malfunctions due to noise from a power line, for example, when the user presses the cancel key 9 to initialize the microcomputer 1, the reset signal R is canceled. and,
When the press of the cancel key 9 is released, the reset signal R is activated again.
rises and the microcomputer 1 is initialized during a period when the voltage is below a predetermined level.

At this time, since there is no change in the operating voltage Vd, the delay circuit 30
The output of maintains a logic "1" signal.

Therefore, the microcomputer 1 determines that the generation of the reset signal is not due to the cancellation of the power outage, but is due to the pressing operation of the cancel key 9, and displays a blank display on the display section 6.

In this way, the delay circuit 3 is provided which responds to the power supply voltage detection output of the reset circuit 4 to output a signal after a certain period of time T from the generation of the reset signal R. 30
It is determined whether a power outage has occurred based on the output of It is possible to reliably notify the user and, for example, if the device is in use, quick measures such as re-cooking can be taken.In other words, the reliability of the power outage notification can be improved.

In the above embodiment, the display unit 6 is used as a power outage notification means.
However, the power outage may be notified by, for example, lighting a light emitting diode or lamp, or operating a buzzer.

In addition, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without changing the gist.

(Effects of the Invention) As described above, according to the present invention, it is possible to provide a highly reliable cooking appliance that enables reliable power outage notification.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a conventional microwave oven control circuit, Figure 2 is a configuration diagram specifically showing the main parts of Figure 1, Figure 3 is a signal waveform diagram of each part in Figure 2, and Figure 4. 5 is a configuration diagram of a control circuit showing an embodiment of the present invention, FIG. 5 is a specific configuration diagram of the main part of FIG. 4, and FIG. 6 is a diagram showing the arrangement position of the display section in the same embodiment. FIG. 7 is a signal waveform diagram of each part of FIG. 5, and FIG. 8 is a flowchart for explaining the operation of the same embodiment. DESCRIPTION OF SYMBOLS 1...Microcomputer, 4...Reset circuit, 6...Display part, 9...Cancel key, 30...Delay circuit. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] A cooking appliance that has a built-in microcomputer and performs cooking under the control of the microcomputer includes a reset circuit that supplies a signal from the microcomputer HeliCera 1 to the microcomputer in response to the rise of the power supply voltage, and a reset circuit that supplies a signal to the microcomputer from the reset circuit. A cancel key that controls the supply of the reset signal and the power 8Pi of the reset circuit.
a delay circuit that outputs a signal after a certain period of time from the generation of the reset signal in response to the voltage detection output; and a determination as to whether or not there is a power outage based on the output of the delay circuit when the reset signal is supplied to the microcomputer. 1. A cooking appliance characterized by comprising a determining means for performing this, and a notifying means for notifying when the determining means determines that there has been a power outage.